Cooling systems for turbocharger mechanisms

ABSTRACT

A cooling system for turbocharger mechanisms for the purpose of cooling the turbocharger mechanism when the vehicle engine has been shut off, thus preventing damage which may result from residual heat in the turbocharger. The system includes an auxiliary pump and conduits bypassing the engine oil pump, the auxiliary pump being controlled in part in its operation by a temperature responsive switch installed in the exhaust portion of the turbocharger. The temperature responsive switch is in an electric circuit with a pressure responsive switch operated by the engine oil system, the arrangement being such that the auxiliary pump will operate when the engine is shut off as long as an elevated temperature exists in the turbocharger mechanism.

United States Patent 1191 Rust [ COOLING SYSTEMS FOR TURBOCHARGERMECHANISMS [76] Inventor: Donald Rust, Star Rt., Box 20c, St. Paul,Oreg. 97137 [22] Filed: Dec. 18, 1972 [21] Appl. No.: 316,044

[56] References Cited UNITED STATES PATENTS Newcomb 3,043,092 7/1962Addie et a1. 60/13 3 ,045,419 7/1962 Addie et al. 60/13 3,045,420 7/1962Addie et a1. 60/13 3,486,582 12/1969 Carter et a1 60/39.08 3,626,69312/1971 Guillot 60/39.08

FOREIGN PATENTS OR APPLICATIONS 702,551 1/1965 Canada 60/39.08

[451 Aug. 6, 1974 Primary Examiner--Carlton R. Croyle AssistantExaminer-Warren Olsen Attorney, Agent, or Firm-Eugene M. Eckelman 5 7ABSTRACT A cooling system for turbocharger mechanisms for the purpose ofcooling the turbocharger mechanism when the vehicle engine has been shutoff, thus preventing damage which may result from residual heat in theturbocharger. The system includes an auxiliary pump and conduitsbypassing the engine oil pump, the auxiliary pump being controlled inpart in its operation by a temperature responsive switch installed inthe exhaust portion of the turbocharger. The temperature responsiveswitch is in an electric circuit with a pressure responsive switchoperated 'by the engine oil system, the arrangement being such that theauxiliary pump will operate when the engine is shut off as long as anelevated temperature exists in the turbocharger mechanism.

2 Claims, 4 Drawing Figures COOLIING SYSTEMS FOR TURBOCI-TARGERMECHANISMS BACKGROUND OF THE INVENTION This invention relates to new anduseful improve ments in cooling systems for turbocharger mechanisms.

Turbocharger systems have heretofore been used for internal combustionengines and employ turbine-like input means driven by the exhaust gasfor injecting the air into the engine. Since the exhaust gas serves asthe driving power, portions of the turbocharger mechanism, particularlyturbine portions such as bearings, are subjected to high temperatureconditions. To cool and lubricate these parts, it is customary toprovide oil circulating systems therewith.

Such cooling systems employ pump means operated by the vehicle engine.Thus, as long as the vehicle engine is operating, the pump operates tocool the turbocharger. When the engine is shut off, however, the coolingpump also is shut of. Such amounts to a serious disadvantage in thateven though the engine has been shut down, the residual heat in theturbocharger mechanism builds up for a short time and is capable ofcausing damage to working parts and seals of the turbocharger mechanismthe same as if the mechanism were operating without being cooled.Another disadvantage of present cooling systems is that the residualheat which builds up causes the oil to coke and such coke deposits willin time plug the return line.

SUMMARY OF THE INVENTION According to the present invention and forminga primary objective thereof, a cooling system for a turbochargermechanism is provided which maintains a cooling function even though thevehicle engine has been shut off whereby to carry away residual heatwhich otherwise may damage seals and portions of the turbochargermechanism.

A more particular object of the present invention is to provide acooling system of the type described which is controlled by a pressureresponsive mechanism in the main cooling system so as to be placed in acondition for operation when the engine is stopped, and also includingtemperature responsive means in the turbocharger mechanism whichfunctions to control operation of the auxiliary pump under certaintemperature conditions, namely, temperature conditions at which it isdesired that the cooling system be operated.

Another object is to provide a cooling system for turbochargermechanisms of the type described which is simplified in construction andinexpensive to manufacture and install on new or existing systems.

The invention will be better understood and additional objects andadvantages will become apparent from the following description taken inconnection with the accompanying drawings which illustrate a pre ferredform of the device.

BRIEF DESCRIPTION OF THE DRAWINGS FlG. l is a diagrammatic view of acooling system for turbocharger mechanisms embodying features of thepresent invention;

FIGS. 2 and 3 are detailed views of portions of such system; and

FIG. 4 is a fragmentary portion, shown diagrammatically, of a modifiedform of structure.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT With particular referenceto FIG. I, the numeral 10 designates generally and diagrammatically aconventional turbocharger mechanism and associated with an engine 12shown in dotted lines. Such turbocharger mechanism comprises a housing14 divided in separate compartments by a wall 16. One side of theturbocharger mechanism comprises the air inlet side and has manifoldmeans 118 leading into and leading out of the housing. The exhaust sideof the turbocharger mechanism also has manifold means 20 leading intoand out of the exhaust side of the housing. The turbocharger mechanismillustrated includes the usual turbine structure 22, shown in dottedlines, which is driven by the force of the exhaust gas and in its drivenrelation injects the air into the engine.

Also, as is customary, portions of the turbine structure 22, such asseals and bearings, are cooled and lubricated by an oil circulatingsystem therethrough. The oil circulating system of the turbochargermechanism is in communication with an inlet passage 24 and an outletpassage 26. Passages 24 and 26 are associated with the oil coolingsystem of the vehicle engine 12, the numeral 28 designating the usualengine oil pump which circulates oil from the sump 30 through theturbocharger mechanism. This pump is operated by the engine and thus hassimultaneous on and off operation therewith.

It is evident that since the pump 30 is inoperative when the engine 28is shut off, the oil circulation to the turbocharger mechanism also iscut off. Since such structure is subjected to high temperatures, theresidual heat therein will build up as soon as the engine 28 is shutdown. Such causes damage to parts of the turbocharger mechanism, and itis the function of the present invention to prevent the build up ofresidual heat, as will now be described.

Connected between the inlet passage 24 and the sump 30 and bypassing thepump 28 is a conduit or line 32 in which is incorporated an electricallyoperated pump 34. Operation of this pump is controlled by a temperatureresponsive device 36 and a pressure responsive device 38. Temperatureresponsive device 36 is mounted in the exhaust side of the turbochargermechanism and is of a well known structure, such as a thermostat orpyrometer, connected to a source of potential 48 such as a storagebattery, and pressure responsive device 38 is connected in the inletpassage 24. A wire 42 connects the temperature responsive device 36 topressure responsive device 38, and a wire 44 connects pressureresponsive device 38 to the pump 34 such electrical connection being inseries circuit. Temperature responsive device 36 is of a structure whichcloses the circuit from battery 40 to wire 42 at and above a selectedtemperature, and pressure responsive device 38 is of a structure whichopens the circuit between wires 42 and 44 when the pump 28 is operatingbut closes such circuit when the pump 28 is not operating. FIG. 2illustrates an exemplary structure of a pressure responsive device whichmay be used herein wherein wire 42 is connected to a contact an arrangedto be engaged by a projecting contact finger 48 of a flap-type valve 50when said valve is closed. The wire 44 is connected to the finger 48,and the arrangement is such that as long as pressure does not exist inthe passage 24, the flap-type valve 50 is pulled closed by a tensionspring 52. This establishes a circuit between wires 42 and 44. However,when pump 28 is in operation, as when the engine 12 is on, the finger 48leaves the contact 46 and no circuit exists between wires 42 and 44 andpump 34 cannot operate.

Temperature responsive device 36 has a setting such that it will closethe circuit between the battery 40 and wire 42 under selectedtemperature conditions. Preferably, the setting is such that a circuitwill exist in the wire 42 at temperatures within the range of normaloperating temperatures of the turbocharger mechanism and at anytemperature thereabove. It will be seen that even though a circuit maybe established between battery 40 and wire 42 when the engine isoperating, pump 34 remains inoperative since the pressure responsivedevice 38 cuts off the circuit between wires 42, 44. With the circuitrybeing established, however, up to the device 38, a complete circuit tothe pump 34 will be closed immediately upon the engine 28 being shutoff. Thus, in the operation of the system, the pump 34 will beinoperative as long as the engine 28 is running, but as soon as thevehicle engine is shut off, such pump will start up to cool theturbocharger mechanism, provided of course that the temperature of theturbocharger mechanism is above the selected set temperature of thetemperature responsive device 36.

An indicator light 54 is connected in wire 44 and comprises visualindicating means that pump 34 is in operation. This indicator light maybe mounted on the dash of the vehicle.

A bypass wire 56 extends from the battery 40 to the pump 34 and has anormally open push button switch 58 therein. By means of this switch,the operator can start the pump 34 at any time desired, such as beforestarting the engine to lubricate the parts of the turbochargermechanism.

With reference to FIG. 3, the connection of conduit 32 into the passage24 preferably is accomplished by a tee 59 and includes a flap valve 60which will move to its dotted line position and close off conduit 32when the pump 30 is in operation to prevent return flow through pump 34.When pump 34 is in operation, the flap valve will move to its full lineposition. This valve allows independent flow from either passage 24 orconduit 32 without return or backflow in the inoperative line.

With reference to FIG. 4, a timer 62 may be connected into line 56instead of pushbutton 58. Such timer can be manually or automaticallyoperated as desired to cause the pump 34 to function.

According to the invention, a cooling and lubricating system is providedwhich is put in operation when the main cooling system of the engine hasbeenshut down.

Such system provides adequate protection of the bearings and seals andother parts and will provide for much longer and efficient operation ofsuch parts. Also, the present system reduces coking of the oil andprevents plugging of the return line.

It is to be understood that the form of my invention herein shown anddescribed is to be taken as a preferred example of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of my invention, or thescope of the subjoined claims. For example, valve 60 may be omittedsince no particular problem will usually exist in backflow through pump34 when the latter is inoperative.

Having thus described my invention, 1 claim:

1. A cooling system for engine turbocharger mechanisms comprising:

a. a main engine driven pump,

b. fluid supply means,

0. main passage means from said supply means connecting said pump tosaid turbocharger mechanism for pressure supply of fluid to the latter;

d. an auxiliary pump,

e. an electric circuit,

f. motor means in said electric circuit driving said auxiliary pump;

g. passage means communicating with said fluid supply means andconnecting the auxiliary pump and into the main passage means inby-passing relation to the main pump,

h. pressure responsive means in the passage means of said main pump,

i. temperature responsive means in said turbocharger mechanism,

j. switch means in said circuit operable by said pressure responsivemeans,

k. said switch means being arranged to open the circuit to the drivemeans for said auxiliary pump when said main pump is operating and toclose the circuit to the drive means for said auxiliary pump when saidmain pump is not operating,

. said temperature responsive means being in said electric circuit inseries with said switch means and arranged to close the circuit only atselected temperature levels wherein said auxiliary pump is placed inoperation only when the main pump is not operating and the temperatureof the turbocharger mechanism is at a selected level deter mined by thetemperature responsive device.

2. The cooling system of claim 1 including a manually operated switch insaid circuit for operating the auxiliary pump.

1. A cooling system for engine turbocharger mechanisms comprising: a. amain engine driven pump, b. fluid supply means, c. main passage meansfrom said supply means connecting said pump to said turbochargermechanism for pressure supply of fluid to the latter; d. an auxiliarypump, e. an electric circuit, f. motor means in said electric circuitdriving said auxiliary pump; g. passage means communicating with saidfluid supply means and connecting the auxiliary pump and into the mainpassage means in by-passing relation to the main pump, h. pressureresponsive means in the passage means of said main pump, i. temperatureresponsive means in said turbocharger mechanism, j. switch mEans in saidcircuit operable by said pressure responsive means, k. said switch meansbeing arranged to open the circuit to the drive means for said auxiliarypump when said main pump is operating and to close the circuit to thedrive means for said auxiliary pump when said main pump is notoperating, l. said temperature responsive means being in said electriccircuit in series with said switch means and arranged to close thecircuit only at selected temperature levels wherein said auxiliary pumpis placed in operation only when the main pump is not operating and thetemperature of the turbocharger mechanism is at a selected leveldetermined by the temperature responsive device.
 2. The cooling systemof claim 1 including a manually operated switch in said circuit foroperating the auxiliary pump.